hide primary menu for anonymous

Hello

Use these modules

http://drupal.org/project/menu_per_role

http://drupal.org/project/menu_access

It will solve your problem

For situations like this I normally use the Context module http://drupal.org/project/context

If you have already created the menu you should be able to follow the directions below to get the menu displaying for logged in users or users of a specific role depending on what you'd like to do.

1. Download and enable the module
2. Visit admin/build/context/list (Drupal 6) or admin/structure/context/list (Drupal 7).
3. Click "Add" to add a new context
4. Give it an appropriate name (e.g., user_account_menu)
5. Tag it, to keep them organized (e.g., user)
6. Under the "Add a condition" drop down menu, select "User role" and then check the box beside either the "Authenticated User" or another role that you specifically need the menu to appear for
7. Uner the "Add a reaction" drop down menu, select "Block" and then locate your Menu Block (e.g., either under the label system or menu) and add it to the region you would like
8. Finally click the save

Now that you've set up a context with conditions and reactions you should be able to see the menu, as an authenticated user (e.g., admin) in the region that you selected.